Profiling of annular workpieces



,March 3, 1970 J. MARCQVITCH 3,498,095

PROFILING OF ANNULAR WORKPIECES Filed March 24, 1966 Q/Ataa Menu/7c United States Patent U.S. CI. 72-87 6 Claims ABSTRACT OF THE DISCLOSURE A machine for profiling workpieces that are figures of revolution produces an article that is accurately dimensioned both axially and radially, and requires at most a minor finishing operation akin to the removal of flash. The profiling is carried out in a space defined between three or more rollers, at least one of which is rotated to impose rotation frictionally on the workpiece. The workpiece is an annulus, and a mandrel is threaded loosely through it and the mandrel ends roll on at least two of the rollers, the workpiece being profiled between the mandrel and a control ring which surrounds the workpiece and limits its diametral spread. Surplus workpiece material is extruded through an escape gap.

This invention relates to the profiling of annular workpieces by rolling.

According to the invention, a machine for profiling an annular workpiece consists of at least three rollers with convex surfaces arranged with their axes parallel and spaced apart to define a space between the roller surfaces, a mandrel located within that space, the mandrel having a central zone and ends projecting from the central zone and supported in rolling contact on the surfaces of at least two of the rollers; a control ring eccentrically surrounding the central zone of the mandrel and engaging at least one of the rollers not engaged by the mandrel and defining with the central zone of the mandrel a recess to entrap a segment of a workpiece located within the control ring and threaded over the central zone of the mandrel, the recess being closed at one axial end and having at or near the other axial end an escape gap for surplus workpiece material; the control ring being axially at least as long as the finished workpiece; means to rotate at least one of the rollers to cause rotation of the mandrel and workpiece and control ring in the space between the rollers; and means to urge the rollers relatively together, so that on deformation of the workpiece it assumes the profile of the recess, surplus material being forced into the escape gap.

An embodiment of the invention is illustrated in the accompanying drawings, in which:

FIGURE 1 is a partly sectioned end view of a machine designed for profiling annular workpieces, using a control ring to control the outside diameter;

FIGURE 2 is a section on the line 22 of FIG. 1; and

FIGURE 3 is a partial sectional view illustrating the rolling of a ring controlled in only one axial direction.

In the machine illustrated, there are three convex rollers 10, 12 and 14, with their axes parallel and arranged triangular-wise, for the roller surfaces to define a profiling space. The rollers and 14 are circumferentially recessed. One of the rollers 14 is mounted on an axle 16 which is displaceable in the direction of arrow A, a second roller 12 is mounted on an axle 20 displaceable in the direction of the arrow B, while the third roller 10 is mounted on a fixed axle 18. The roller 10 is driven by any 3,498,095 Patented Mar. 3, 1970 suitable means which, being irrelevant to the invention, is not illustrated. The machine is shown at the end of a rolling operation.

An annular workpiece 36 surrounds a central zone of a mandrel 38 that is located in the space between the rollers.

The central zone of the mandrel is recessed and profiled to impose the required shape on the inner face of the workpiece. The mandrel ends project beyond the central zone to roll on the surfaces of the rollers 10 and 14. The mandrel is thus floatably mounted in the sense that it is not confined in bearings. A control ring 52 surrounds the workpiece 36. It bears against the surface of the roller 12 and its inner surface profiles the radially outer face of the workpiece. With the central zone of the mandrel, the control ring defines a recess in which a segment of the workpiece is entrapped, the recess being closed at one axial end by a wall 57 of the recess in the mandrel. At the other axial end of the workpiece an escape gap 56 is provided between the mandrel and control ring to ensure complete filling of the profiling space during the rotation of the workpiece, the flash formed by material forced or extruded into the gap being removed in a subsequent operation, such as machining or grinding. Since there is invariably lack of uniformity in the blank workpieces fed to the machine, the amount of surplus material extruded as flash will vary from one workpiece to another, care being taken to ensure that no workpieces below a known minimum volume are used.

Suitable stop means is provided to limit the approach of the rollers towards one another, and thus to control the wall thickness of the workpiece. The stop means might take the form of surfaces such as flanges (not illustrated) on the roller 12 to make contact with the ends of the mandrel, or might be known devices to limit the travel of the rollers 12 and '14 along the directions of the arrows A and B.

Axial misalignment of the mandrel, rollers and control ring is prevented by the stepped construction of the mandrel ends and by matching the axial length of the control ring with that of the recess in the surfaces of the rollers 10 and 14.

It will be seen that one of the main features of the machine is the precise control of all dimensions of the finished article-outer diameter, wall thickness and axial lengthobtained by entrapping a segment of it around the entire circumference within a fully enclosed space (save for escape gaps) so that the finished article comes from the machine fully and precisely finished with no after operations other than the minor one of removal of flash.

The operation of the machine will easily be understood. The rollers are moved apart to allow the mandrel and the workpiece threaded over it, with the control ring loosely surrounding the workpiece, to be located within the profiling space between the rollers; and the rollers are moved together and simultaneously rotated by driving the roller 10 to rotate the workpiece and control ring, and mandrel. The workpiece which is initially, of course, of lesser diameter than the inner diameter of the control ring and lesser length axially than the length of the profiling recess in the mandrel is squeezed within the enclosed recess within which it is entrapped and which diminishes in volume as profiling proceeds. Diametral spread of the workpiece is limited by the workpiece coming into contact with the inside face of the control ring. Axial or lateral spread is limited by the walls of the recess in the mandrel. Wall thickness is limited by the stop means for the advance of the rollers. Surplus material, when the recess has been totally filled, extrudes into the gaps to form flashes.

When the profiling operation is complete, the rollers are moved apart, the mandrel and workpiece removed, the

I 3 mandrel taken out of the cavity of the workpiece, and the workpiece is tapped out of the control ring.

It will be appreciated that, when entrapment in the recess is referred to, what is meant is that a segmentof the annular workpiece is confined in the recess defined by the mandrel recess and the control ring inner face, and that, in the space or zone in which deformation is taking place, the recess is closed at the inner and outer faces of the segment. It is also closed at both its axial ends (at least during the later stages of profiling), except where the escape gap is provided. The recess is, of course, open at the other two sides to allow the ring to rotate and to bring its periphery progressively through the recess for profiling.

The machine is versatile in operation in that the sizes or inner profiles of workpieces and of the finished products can be easily and quickly varied merely by removing the floating mandrel and inserting another which may be one of a set, with a different diameter or a different profile. By using another control ring of different size or profile, an article with a correspondingly different outer size or profile is produced.

It is pointed out that the deforming pressure applied to the workpiece is over a small contact area between the workpiece and the mandrel, while the force applied to the mandrel itself can be considerable. Very large forces per unit area are thus generated on the workpiece for moderate forces applied to the mandrel, and this brings within the scope of machine the production of many components which are not capable of being made by conventional profiling systems. The deformation resulting from the large forces generated can therefore be substantial, and the control of the workpiece in all dimensions enables the large deformation to be put to effective use, while ensuring that the finished products are precisely uniform.

While the drawings show three rollers, it is pointed out that there may be more than three rollers, with their axes parallel and arranged to surround a space, the rollers being movable relatively together, and at least one being driven.

I claim: v

1. Apparatus for profiling an annular workpiece, consisting of at least three rollers with convex surfaces arranged with their axes parallel and spaced apart to define a space between their convex surfaces; a mandrel cated within that space, the mandrel having a central zone and ends projecting from the central zone and supported in rolling contact on the surfaces of at least tWo of the rollers; a control ring eccentrically surrounding the central zone of the mandrel and engaging at least one roller not engaged by the mandrel and defining with the central zone of the mandrel a recess to entrap a segment of a workpiece located within the control ring and threaded over the central zone of the mandrel, the recess being closed at one axial end and having at or near the other end an escape gap for surplus workpiece material; the control ring being axially at least as long as the finished workpiece; means to rotate at least one of the rollers to cause rotation of the mandrel and workpiece and control ring in the space between the rollers; and means to urge the rollers relatively together so that on deformation of the workpiece it assumes the profile of the recess, surplus material being forced into the escape gap.

2. The apparatus of claim 1 in which the mandrel is recessed in its central zone.

3. The apparatus of claim 1 in which the escape gap is defined by and between a surface of the mandrel and a surface of the control ring.

4. The machine of claim 1 in which means is provided to prevent relative axial displacement between the mandrel, the rollers on which its ends are adapted to roll, and the control ring.

5. The apparatus of claim 1 in which the support for the ends of the mandrel extends all the way to the central zone of the mandrel thereby to minimize flexing of the mandrel.

6. The apparatus of claim 1 in which the total length of the mandrel ends in rolling contact with said at least two rollers is at least as great as the axial length of said central zone.

References Cited UNITED STATES PATENTS 705,518 7/1902 Einfeldt 72107 721,210 2/1903 Mannesmann 72224 954,245 4/1910 Andrews 72107 999,467 8/1911 Sack 72178 1,045,161 11/1912 Machlet 72107 1,493,836 5/1924 Wurster 72107 1,779,185 10/1930 Meiser et al. 72-178 2,508,517 5/1950 Hill 72370 3,230,606 1/1966 Saito et al 72111 X 3,345,845 10/ 1967 Marcovitch et al 7291 3,382,693 5/ 1968 Rozhdestvensky et al. 7287 899,436 9/1908 Ritter 721 11 CHARLES W. LANHAM, Primary Examiner E. M. COMBS, Assistant Examiner US. Cl. X.R. 

